The present invention relates to a device for recording data to a disc medium to which data may be added, and more particularly, to a recording controller for adding new data to a disc medium, to which a disc address corresponding to a predetermined data format is recorded beforehand, from the end of previously written data.
FIGS. 1 to 3 indicate the logic format of data recorded to a digital versatile disc (DVD).
FIG. 1 shows an error correction code (ECC) block. The ECC block includes information data, which is configured by 172 columns of bytes and 192 rows of bytes. The ECC also includes an outer code parity (PO) and an inner code parity (PI). The PO is added to each of the 172 columns of bytes and has a data length of 16 rows of bytes. The PI is added to each of the 192 and 16 rows of bytes and has a data length of 10 columns of bytes.
Referring to FIG. 2, the information data of the ECC block is divided into 16 units. Each unit is referred to as a data sector, each consisting of 12 rows of data. Each of the 16 rows of the PO is sequentially moved next to one of the 16 data sectors to configure 16 recording sectors.
FIG. 3 indicates the format of a data sector. Twelve bytes of header data, which includes a data address, are added to the head of each data sector. The data sector includes 2048 bytes of main data and 4 bytes of error detection code (EDC) data.
When data is recorded to a DVD, 8 bits of data is modulated to 16 bits of data, and a synchronization signal is added to each of the sixteen bits of data to perform 8-16 modulation. The 8-16 modulation generates the modulation data of FIG. 4.
Referring to FIG. 4, a frame of DVD recording data includes 32 bits of synchronization signal data (indicated as sync) and 1456 bits of modulated data. That is, 728 bits of original data undergoes 8-16 modulation to generate 1456 bits of modulated data, and 32 bits of the synchronization signal (sync) is added to the head of the modulated data. This configures the DVD recording data frame. In the DVD, 26 frames of recording data configure a single sector. The configuration of a single sector of recording data in a DVD is shown in FIG. 4.
The modulated data is recorded along a single spiral track that extends along a disc medium. The track is a groove extending between lands in a disc. The groove slightly wobbles. A wobble signal having a predetermined cycle is extracted from the wobbling of the groove.
The disc medium includes land prepits (LPP), which contain address information, formed at predetermined intervals along the track. More specifically, an LPP is provided for each data recording region, which corresponds to two of the above frames. The address information of the LPP indicates the position of a data recording region on the disc.
Data is recorded on the data recording region in accordance with the address information of the LPP. The address information of the LPP may be used to add data to the disc medium. Data is added in the following manner.
When ending the recording of data, the address of the data is recorded as address information in a certain recording region of the disc medium. When recording additional data, the position for starting the recording is determined by referring to the address recorded in the certain recording region. The recording of the data is then started at a timing in which the spot of a laser beam emitted to the disc medium coincides with the recording initiation portion. This enables the adding of data.
The address information of the disc medium that was recorded in the certain recording region based on the LPP to indicate the position where data recording ended may not accurately indicate the position where data recording actually ended. As a result, additional data may not be properly recorded when data that has already been actually recorded does not correspond to its allocated data recording region.
FIG. 5A shows an example in which a single block of actually recorded data is longer than a data recording region allocated for a single block. In this case, the end (DE) of the recorded data exceeds the end (AE) of the recording region block of the disc medium. The recording end position of the previous data, or the address information representing the end of the data, is recorded in the certain data recording region. However, the address information corresponds to the address of the end of the data recording region allocated for a single block (AE in FIGS. 5A and 5B). Thus, when data is added based on the address information obtained from an LPP signal, data is recorded from the end (AE) of the data recording region. As a result, data is rewritten on the previously recorded data. Thus, the previously written data cannot be correctly read.
FIG. 5B shows an example in which a single block of actually recorded data is shorter than a data recording region allocated for a single block. In this case, the end (DE) of the recorded data does not reach the end (AE) of the recording region block of the disc medium. Thus, when data is added based on the address information obtained from an LPP signal, data is recorded from the end (AE in FIG. 5B) of the recording region. In this case, a vacant region is formed between the previously recorded data and the head of the added data. As a result, data becomes non-continuous.